* {
    margin: 0;
    padding: 0;
}

a {
    text-decoration: none;
}

.clearfix:before,
.clearfix:after {
    content: "";
    display: table;
}

.clearfix:after {
    clear: both;
}

.clearfix {
    *zoom: 1;
}

.app {
    position: relative;
    width: 320px;
    height: 480px;
    background-image: url('../images/game_bg.jpg');
    margin: 20px auto;
}

.hp {
    position: absolute;
    width: 180px;
    height: 16px;
    top: 66px;
    left: 63px;
    background-image: url('../images/progress.png');
}

.score {
    position: absolute;
    top: 2px;
    left: 60px;
    font-size: 30px;
    color: white;
}

.rules {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 30px;
    line-height: 30px;
    text-align: center;
    background-color: rgba(0, 0, 0, .4);
}

.rules a {
    color: white;
}

.start_btn,
.restart_btn {
    margin: 200px auto 0;
    width: 180px;
    height: 50px;
    line-height: 50px;
    border-radius: 25px;
    cursor: pointer;
    text-align: center;
    font-size: 32px;
    color: white;
    background-color: #DD4008;
}

.restart_btn {
    margin-top: 34px;
}

/* 游戏规则遮罩 */
.rules_info {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    width: 320px;
    height: 480px;
    text-align: center;
    color: white;
    background-color: rgba(0, 0, 0, .4);
}

.rules_info h3 {
    margin: 90px auto 30px;
}

.rules_info p {
    line-height: 35px;
}

/* 遮罩2 */
.restart {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    width: 320px;
    height: 480px;
    color: white;
    text-align: center;
    background: rgba(0, 0, 0, .6);
}

.restart p {
    color: pink;
    font-size: 40px;
    font-family: "黑体";
    margin: 120px auto 0;
    text-shadow: 1px 2px 0px white;
}